I think my dana 70 is about to give it up. Lots of play between the pinion and ring gear. The pinion turns about a half turn before it catches. Not good. I've noticed it getting progressivly worse since I've owned the truck. Time to replace it before it strands me. I can get a dana 80 with 4.10 and LSD from a '97 dually CTD for a really good deal. I was wondering if there is a difference in width between a dually axle and a single wheel axle. And if so, what is the difference?

I'm also aware of the bigger 9/16" lug studs on the newer axles. I think I can use old body Furd F'd350 4x4 front studs in my front rotors so they will match the new rear axle stud size.

 

I don't know if the wms distance will be okay for you or not, but I THINK it is a little wider -- guy who did a swap the other way said he had to space out the dually wheel for tire clearance to the springs. I also remember reading something about it being a pain to modify the e-brake cables and spring clamps to make the 80 fit?

There is a guy running an 80 on his old first gen, though, who posts on www.diesel-central.com, so it can, like most anything with enough patience, be done.

By the way -- I don't think it is backlash causing your play, because you'd have to be missing teeth to make half a turn, rather a combination of things including a worn out carrier -- check out Redleg's posts about the cross pin coming out of his carrier and jamming into the pinion . . .